Today's cameras generally make use of CCD or CMOS elements as light detecting sensors. Due to the production process, e.g. manufacturing from a silicon wafer, these sensors are generally flat. As a consequence, the camera optic needs a special lens to prepare the incoming light for the flat camera sensor. While this lens does not constitute a problem for professional cameras regarding weight and size, the situation is different for camera applications which need a compact camera. For example, portable devices like cell phones or PC/laptop cameras need to be lightweight and small. A camera working without a lens for imaging the incoming light onto a flat camera sensor would thus be desirable.
A known imaging system without the need for an additional lens is the human eye. Due to the spherical shape of the retina no additional lens apart from the eye lens located below the iris is necessary. However, with current semiconductor based production processes it is not possible to produce CCD or CMOS elements on a sphere.
DE 10 2005 052 176 A1 discloses a video camera having a curved sensor area. The curved sensor area is achieved either with a special bundle of optical fibres, which guide the incoming light onto a flat sensor, or by arranging a plurality of individual sensor elements on a spherical surface. While the former solution needs a rather expensive fibre bundle, the latter solution requires a lengthy and difficult production process.